GB593574A - Improvements in or relating to mechanical presses - Google Patents

Abstract

593,574. Mechanical presses. HARPER, H. Feb. 16, 1944, No. 2870. [Class 87 (ii)] Between a ram and a platen is disposed 'a deflectable spring member which transmits the pressure from the ram to the platen, and variations in the pressure applied to the spring member are indicated by means which indicate the variations of deflection of the spring member. Two examples are described, in each of which the ram 13 is an extension of a screw jack. (1) (Fig. 2). The ram 13 presses upwardly on the platen 15 through a spring plate 17 and ring 16. The indicating means comprise two green lamps 26, 27 of 4.5 volts, 3 amps. each and two red lamps 28, 29 of 4 volts 0.5 amps. each. When the ram exerts no pressure on the spring plate 17, the two green lamps are alight and the two red lamps are not alight, the circuit for lamps 26, 27 passing through spring contacts 22, 23 respectively. When pressure is applied by the ram, contact 22 is broken and the circuit for lamp 26 passes through lamp 28. Lamp 28 is thus lit and lamp 26 goes out. On further application of pressure by the ram, contact 23 is broken, the circuit for lamp 27 passes through lamp 29, lamp 29 is lit and lamp 27 goes out. The pressure is thus indicated in two stages, but may be indicated in one or more than two stages. (2) (Fig. 3). A lever 31, pivoted at 32, bears at one end 33 on the spring plate 17 and at the other end passes over a scale 30, which may be marked by a line to indicate one pressure and other lines of varying colours to indicate subsequent pressures as they are successively reached.